Spi 34-211-3 Plug Thread Gage 3-56 6H Single End Go

Product Description

The SPI 34-211-3 is a single-end Go plug thread gage designed to verify internal thread conformance on 3-56 UNC threaded features. Manufactured from steel, it is built to ANSI standards and ships with a NIST-traceable calibration certification, making it suitable for quality control applications where documentation is required. The gage accepts a size 0 handle, which is sold separately. At 1 pound, it is a compact, easy-to-handle inspection tool used by machinists, quality technicians, and toolroom professionals to confirm that tapped holes meet 6H tolerance class requirements before parts advance in production or assembly.

This gage is applied wherever precision internal thread inspection is required on 3-56 threaded components. Typical use cases include incoming inspection, in-process quality checks on machined parts, and final acceptance testing in manufacturing and assembly environments. The 6H classification makes it appropriate for standard-fit threaded fastener applications in industries such as electronics, instrumentation, and light mechanical assemblies where fine thread control is critical. The handle is not included and must be sourced separately in the appropriate size 0 format.

Key Features

• Go member only — single-end design for pass inspection of 3-56 internal threads
• 6H thread classification for standard-tolerance internal thread verification
• Steel construction for durability and dimensional stability under repeated use
• NIST-traceable traceability certification included for quality system documentation
• Meets ANSI standards for thread gage performance and dimensional accuracy
• Size 0 handle compatibility — handle sold separately

Compatibility

Designed for use with size 0 plug thread gage handles to inspect 3-56 UNC internal threads manufactured to 6H tolerance class specifications.

Installation Notes

Thread gages are inspection tools and do not require permanent installation. Insert the gage into the appropriately sized handle before use. Apply consistent, hand-pressure-only force when gauging — do not force, impact, or use power tools with thread gages, as doing so can damage threads and compromise gage accuracy. Store the gage in a protective case away from other metal tooling to prevent nicks and wear that would affect calibration.